James robertson



(No Model.)

"J. ROBERTSON. HYDRAULIC PRESSING APPARATUS.

No. 560,936. Patented May 26,' l896.

l Th Witnasew;

ANDREW REHANAM. PHUTO-UTHQWASHINGION B C.

UNITED STATES PATENT OFFICE.

JAMES ROBERTSON, OF MANCHESTER, ENGLAND,

HYDRAULIC PRESSING APPARATUS.

SPECIFICATION forming-part of Letters Patent No. 560,935, dated May 26, 1896. Application filed November 30,1895. Serial No. 570,674. (No model.) Patented in England March 4,1893,N0.4,'722.

- ratus, (for which I have received Letters Patv supported on a suitable base Q ent in Great Britain No. 4,722, dated March 4, 1893,) of which the following is a specification. 7

This invention relates to hydraulic pressing apparatus for use in shaping metals by the forging process, wherein liquid-actuating rams are reciprocated to transmit power to liquid-actuated rams of the press proper to alternately raise and lower the forging-head. The particular object of the invention here disclosed is to provide auxiliary liquid-forcing means to be brought into operation as desired to vary the stroke of the forging-head according to the work in hand, whereby I am enabled to employ a direct-acting steam-engine for driving the liquid-actuating rams and at the same time provide for differentlength strokes of the forging-head without waste of steam. Using a short-stroke engine, the auxiliary liquid-forcing means are brought into play when a longer movement of the forging-head is desired than can be produced by the engine.

The drawings which accompany and form part of this specification illustrate an embodiment of the invention.

Figure 1' shows a sectionalized side elevation of the complete apparatus. Fig. 2 shows an end elevation of the same. Fig. 3 shows a top plan view.

Q designates the base-frame of the press, in the overhanging portion of which there is arranged the cylinder J which receives the ram K of the forging-head. On the upper side of this overhanging part of the frame there is mounted the cylinder P, which receives ram P carried by cross-head P this cross-head being connected by side rods P with the forging-head.

H designates a direct-acting steam-engine, whose piston-rod H is connected with a rectangular frame A carrying rams A and A projecting toward each other and entering, respectively, cylinders l and l, which are Cylinder I is connected by suitably-valved pipe 0 with press-cylinder J whereas cylinder I connects by suitably-valved pipe P with presscylinder P.

It will be obvious that the arrangement above described will operate to move the forging-head of the press up and down when a suitable supply of water has been introduced into the pipes and the engine is set in operation. Now this is all well enough for work capable of performance by the short stroke of the engine; but as frequently a longer movement of the forging-head is desired than can beimparted by this short stroke of the engine I provide a set of auxiliary pumps of common form, of which there are here shown six, (designated S, S S S and S and which may be employed, through means presently to be described, for the purpose of drawing liquid from the cylinder J and forcing this liquid into cylinder P for the purpose of raising the forging-head higher than the position to which it is brought by the engine, and vice versa for moving it downward through a greater distance.

Three of the pumps, S S and S, have their suction ends in communication with a pipe S which enters the forcing-cylinder J of the press, and-the discharging ends of these three pumps communicate with a pipe U,

' which enters the return-stroke cylinder P of the press. Thus with these pumps in action and the waterways properly opened liquid is drawn from the cylinder J and forced into the cylinder P thereby raising the forginghead to a higher position than reached under impulse of the engine. The other three pumps, S, S and S connectby suction-pipe S with cylinder P and by discharge-pipe U with cylinder J so that when these pumps are brought into operation liquid is drawn from cylinder]? and forced into cylinder J thereby lengthening the downward movement of the forging-head over that produced by the engine. Stop-cocks S and S are provided in the pipes S and S to control communication between the pumps and the presscylinders, and these valves willhave handles for the attendant to manipulate.

When the work in hand only requires such movement of the forging-head as can be produced by the engine, then both cocks S and S are closed. When the pumps are used,

these cocks are alternately opened and closed to produce the lengthening of the forging heads movement.

It may be here stated that each of the liquid-forcing rams A and A is of but onesixth the water-displacing mass of each of the forging-head pistons K and P \Vhat I claim as my invention is as follows:

1. In hydraulic pressing apparatus, the combination with the press having a forging-head carrying advancing and retracting liquid-actuated rams and cylinders inelosing the same, of a pair of connected liquid-actuating rams, cylinders inelosing the latter, suitable waterways connecting the said cylinders respectively with those inelosing -the advancing and retracting rams of the press, means for reciprocating the liquid-actuating rams, and auxiliary pumping means communicating with the press-cylinders and arranged to transfer liquid from one to the other, substantially as and for the purpose described.

2. In hydraulic pressing apparatus, the

combination with the press having a forging-head carrying advancing and retracting liquid-actuated rams and cylinders inelosing the same, of a pair of connected liquid-actuating rams, cylinders inelosing the latter, suitable waterways connecting the said cylinders respectively with those inelosing the advancing and retracting rams of the press, means for reciprocating the liquid-actuatin g rams, a set of auxiliary pumps communicating by suction and discharge pipes with the press-cylinder inelosing the retracting mm, a similar set of pumps communicating in like manner with the cylinder inelosing the advancing press-ram, and valves in the suctionpipes, substantially as described.

In testimony whereof I have signed my name to this specification, in the presence of two subscribing witnesses, this 29th day of October, A. D. 1895.

JAMES ROBERTSON.

Witnesses:

ARTHUR O. HALL, JOHN W. THOMAS. 

